The present disclosure relates generally to a method of designing a set of masks for a lithographic design level, and more particularly to a method of generating shapes for multiple sets of multiple lithographic masks for patterning semiconductor fins through use of a directed self-assembly material, and an apparatus for implementing the same.
Optical lithography has inherent limitations for minimum dimensions due to finite resolution of optical radiation. Directed self-assembly (DSA) offers an alternative method for forming periodic structures such as a one dimensional array of semiconductor line structures. In order to convert the array of semiconductor line structures into semiconductor fins, it is necessary to etch away portions of the semiconductor line structures employing lithographic masks. However, corner rounding, overlay variations, and other lithographic limitations apply when the semiconductor line structures are lithographically patterned, thereby compromising the reproducibility and reliability of semiconductor fins thus obtained.